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    <title>Document</title>
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<body>

    <script>

        var arr = [1, 2, 3, 1, 2, 3, 4, 2]   // 2

        function myIncludes(arr, n) {
            // 思路：拿数组中的每一个值出来比较

            var flag = false;
            for (var i = 0; i < arr.length; i++) {
                if (arr[i] === n) {
                    // return true
                    flag = true;
                }
            }
            // return false
            return flag
        }

    </script>

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